Older athletes can be much younger, physically, than they are in real life, according to a new study of participants in the coming Senior Olympics. The study found that the athletes’ fitness age is typically 20 years or more younger than their chronological age, providing a clear inspiration to the rest of us to get out and start moving more.

I wrote last year about fitness age, a concept developed by researchers at the Norwegian University of Science and Technology in Trondheim who had taken note of epidemiological data showing that people with above-average cardiovascular fitness generally had longer life spans than people with lower aerobic fitness. So at any given age, fit people were relatively younger than were people who were out of shape.

But the researchers decided that their insight was not useful unless people could easily determine their fitness age. So using a mobile exercise laboratory, they went out and tested the fitness and health of more than 5,000 Norwegian adults and used the resulting data to create a sophisticated algorithm that could rapidly calculate someone’s aerobic capacity and relative fitness age based on his or her sex, resting heart rate, waist size and exercise routine.

They then set up a beguilingly simple online calculator that people could use to determine their fitness age.

When I wrote about the calculator last year, Dr. Pamela Peeke took note. An assistant professor of medicine at the University of Maryland and board member of the foundation that runs the National Senior Games — which are informally known as the Senior Olympics — she is also a competitive triathlete.

And biologically, it seems, she is a spring chicken. When she plugged her personal data into the online fitness calculator, it told her that her fitness age is 36.

Chronologically, she is 61.

Delighted, she wondered whether other older athletes would be similarly youthful. And she had a plan for how to find out. Contacting the scientist who had led the development of the fitness age calculator, Ulrik Wisloff, she suggested that together they study a particular group of older people — the participants in this year’s Senior Olympic Games.

The Senior Olympics are a biennial competition for athletes over 50 and consist of a variety of sports, from track and field and swimming to pickleball. To compete, athletes must first qualify regionally.

Nearly 10,000 men and women aged from 50 to 100 have qualified for this year’s Games, which begin on Friday in and around Minneapolis-St. Paul, in Minnesota.

Senior Olympians are not professional athletes, but most train frequently, Dr. Peeke knew. They tend to be more physically active than other people of the same chronological age.

To see just how their lifestyle affects their biological age, she and Dr. Wisloff asked all of this year’s Senior Olympic qualifiers to complete the online calculator. They set up a special, dedicated site for the participants, so that their data could be isolated. (The fitness calculator itself was unchanged.)

Many of the participants complied, producing more than 4,200 responses.

The results were impressive. While the athletes’ average chronological age was 68, their average fitness age was 43, a remarkable 25 years less.

“This is a massive difference,” Dr. Wisloff says. “I had expected a big difference,” he continued, “since these people have trained for years. However, I was surprised that it was this big.”

The effect was similar for both male and female athletes, he pointed out. Virtually every athlete, in fact, had a lower fitness age than his or her chronological age.

Dr. Peeke and Dr. Wisloff have not yet determined whether athletes in certain of the sports at the Senior Olympics, particularly endurance events such as distance running and swimming, have a younger fitness age, in general, than athletes participating in less-vigorous sports.

But they plan to parse the data extensively in the coming months to answer that question and to look for other patterns among the Senior Olympians. They expect to publish their findings soon.

Even in advance of that information, though, the takeaway message of the data should be inspiring, said Dr. Peeke, who will be competing in the triathlon event at the Senior Olympics.

“A majority of the athletes at the Senior Games didn’t begin serious training until quite late in life, including me,” she said. “We may have been athletes in high school or college. But then, for most of us, jobs and families and other commitments got in the way, at least for a while.”

Few Senior Olympians returned to or began exercising and training regularly until they were middle-aged or older, she said.